For a disease that affects an estimated 3.9 million Americans, the treatment of choice works only about 50% of the time for patients with genotype 1, the most common type of hepatitis C virus (HCV) found in the United States, according to the Centers for Disease Control & Prevention. Sustained response rates are slightly higher in genotypes 2 and 3 (up to 80%).
In July 2006, the company announced that it had entered patients into two cohort studies to extend the duration of treatment with AVI-4065. One cohort will be treated twice daily for 28 days and the second will receive treatment twice daily for 56 days. In previous studies, AVI-4065 showed a favorable safety profile and was well tolerated in all patients, without any drug-related adverse events. According to AVI BioPharma, clinical and viral response data from previous cohorts involving HCV patients are expected to be reported by the end of the third quarter of 2006.